Transcript

(SFX: buzzing of a mosquito) Mosquitoes seem very adept at finding people to bite. But listener Bruce Robertson from Kalamazoo, Michigan, asked how they locate us, since they’re small and don’t fly very quickly. We consulted entomologist Dennis LaPointe of the U.S. Geological Survey’s Pacific Island Ecosystem Research Center in Hawaii. He says mosquitoes follow the plumes of carbon dioxide, or CO2, that warm-blooded animals exhale.

DENNIS LAPOINTE (USGS):
And as they fly upwind into this plume, they’re getting closer and closer to the source of this CO2.

HIRSHON:
Then when they’ve almost reached their target, the backyard pests use other chemical cues, as well their ability to sense body heat and humidity, to home in on their prey. If you’ve got a science question, call us at 1-800-WHY-ISIT. If we use it, you’ll win a Science Update mug. I’m Bob Hirshon for AAAS, the science society.